Many people use mobile or wireless end-user computer-type devices for a variety of purposes. These devices include smartphones, handheld computer-type devices, personal digital assistants (PDAs), laptop computers equipped with a wireless network interface card, etc. Users often use such devices to read and write email messages, access the Internet, download and view image or video files, run applications, etc.
In order to use such mobile devices, the mobile devices must be able to connect to a wireless network. Conventional wireless local area networks (WLANs) are often deployed inside structures such as homes, offices, public and commercial buildings, etc. The WLAN typically comprises one or more wireless access points, such as a wireless router or hot spot, which communicates wirelessly with the mobile device, and allows the mobile device to connect to a wired network (or other network) that is also in communication with the access point. In order to stay connected to such WLANs, the mobile user must usually stay with the range of the access points. This often constrains the effective mobility of a wireless user. The mobile user must stay in the home, office or building to have wireless access to the WLAN, but if the mobile user leaves the premises, the mobile user may leave the range of the wireless access points and thereby lose connectivity to the network. For the IEEE 802.11 standard, also known as Wi-Fi, the range of such access points is about 50 meters for indoor environments and 100 meters for outdoor environments.
Some campuses and urban areas provide broader Wi-Fi coverage areas by placing a number of cooperating Wi-Fi hot spots throughout the campus or urban area. This provides the mobile user with greater wireless access as the mobile user generally can move around the campus/urban area while maintaining wireless connectivity. However, when the mobile user leaves the campus/urban area, the user may lose connectivity, thus constraining the wireless mobility of the user.
This dilemma has been addressed somewhat by cellular networks that allow mobile devices to communicate wireless data with such cellular networks using data communication standards, such as GSM/GPRS (Global System for Mobile Communications/General Packet Radio Service) or EDGE (Enhanced Data rates for GSM Evolution). Such cellular networks generally provide much broader coverage areas than WLANs or Wi-Fi area, so a mobile user will ordinarily have fewer restrictions on mobility when accessing such a cellular network. Further, cellular networks typically can accommodate roaming users by allowing users to stay connected as they travel from one cellular network to another.
Nevertheless, mobile end-user devices often experience interruptions in service due to drop-offs by the network (either Wi-Fi or cellular network). This problem is exacerbated when the user is quickly moving between network cells, hot spots or networks. This can be caused, for example, (i) because the user's wireless access provider/protocol is not compatible with the new cell, hot spot or network, (ii) because the new cell, hot spot or network is overly congested with traffic, (iii) because of faulty hand-off procedures between the cells, hot spots, or networks, or many other reasons.
In addition, a mobile end-user may experience other types of performance problems, including a change of bit rate or bandwidth during the data transmission, and a change in the quality of service (e.g., jitter, latency, data loss, etc.).
Accordingly, there exists a need for a way to alleviate or mitigate the problems experienced by a user of mobile end-user device.